The microwave oven is a very convenient and quick electrical appliance to prepare and heat food: but which are the containers that can be used in the microwave oven and which materials must never be used? Here is a small guide to know which containers to use and which ones are forbidden.

The microwave oven has now become an essential electrical appliance, suitable for fast cooking and ideal for heating food in a short time and evenly, but it is important to know which containers can be used in the microwave oven and which cannot be absolutely used, because they could damage the microwave oven. Let's find out which containers and materials are to be used or not used in the microwave oven: simple indications and rules to make the best use of your electrical appliance without risk.

How to understand if a container is suitable for microwave cooking?

For cooking in the microwave oven it is necessary to use materials that are transparent to the waves. Before seeing specifically which ones to use, here’s  how to perform a simple test: put a glass in the microwave oven with water and heat it at maximum power for 1 minute. If the glass is cold or just warm, and the water is heated, then the container is suitable for this type of appliance. When you buy containers to use for the microwave oven, however, always check that the package is marked with the appropriate wording, or make sure you find the following symbol: three stylized waves superimposed on each other. If you buy precooked foods, however, you will usually find them in containers suitable for use.

Containers suitable for cooking in the microwave oven: from glass to terracotta

Among the most suitable materials for cooking in the microwave oven we find the glass, especially the pyrex, a particular type of glass that does not contain lead. The glass also allows, thanks to its transparency, the vision of food during cooking. On the other hand, do not insert leaded glasses or crystal cups. You can also use plastic, both containers and film, as long as it is a specific type that bears the words "heat resistant, at least 140°": if you use the film, it will not have to touch the food directly, and you will have to pierce it , to allow the steam that will form in cooking, to escape. The plastic that contains PVC, like the yogurt containers, is not suitable, because it could deform and melt, releasing toxic substances on food. To understand if a plastic is suitable, it must show the symbol with the three stylized waves on the package. Plastic and silicone containers are also very practical and economical.

Another material very suitable for the microwave oven is porcelain, except the one with metal decorations (for example those with golden borders). It is also possible to use paper and cardboard dishes and containers, even if they are only indicated to briefly heat the food: if subjected too long to the action of the microwaves, they could ignite. For this there are paper and cardboard containers suitable for the microwave oven. Also clay and terracotta are suitable for the microwave, provided they are enamelled and have no cracks. If the base is not enamelled they could break during cooking. To cover the containers you can use porcelain dishes and glass ceramic lids: if you cover the food to be cooked or to be heated, you will reduce the cooking time, as the steam will be retained and the food will cook or heat quickly.

Which materials you must never use in the microwave oven?

There are some materials that cannot be used in the microwave oven, a list of "forbidden" materials, because they could overheat, deform or release harmful substances that would be transmitted to food. Among the containers never to be used in the microwave oven there are the metal trays, the aluminum foil and the aluminum, but also alloys such as cast iron and copper. These are in fact materials that could cause sparks inside the oven: the metals, in fact, reflect the electromagnetic waves. Among these we also find pots or dishes in stainless steel that are usually used for cooking. The only exception is the crisp plate that is usually supplied with the microwave oven. The crystal containers are also forbidden, as crystal is a material that contains lead, and the containers with metal decorations. Wood and wicker can be used for short cooking and must not crack.